1. Field of the Invention
The present invention relates to a voice coil motor.
2. Description of Related Art
Recently, a portable communication apparatus is provided with a camera module to store an image or a moving image. The camera module includes an image sensor module for converting external light to an image, and a lens for focusing the external light on the image sensor module.
The conventional camera module is problematic in that it is impossible to adjust a distance between the lens and the image sensor module, so that it is difficult to obtain a desired image. However, in order to solve the problem, a voice coil motor for adjusting the distance between the lens and the image sensor module of the camera module is recently developed.
The conventional voice coil motor includes a bobbin receiving a lens, a coil block wound around the bobbin, a magnet facing the coil block, an elastic member elastically supporting the bobbin, and a base supporting the bobbin. The voice coil motor adjusts an interval between the lens received in the bobbin and the image sensor module, using attractive force and repulsive force generated by a magnetic field between the coil block and the magnet.
In the conventional voice coil motor, the coil block is mounted in a direction from an upper surface to a lower surface of the bobbin, and a protrusion is provided on a lower end of an outer circumference of the bobbin to support the coil block.
However, the conventional voice coil motor is problematic in that the protrusion for supporting the coil block is provided on the lower end of the outer circumference of the bobbin, so that all structures for inhibiting rotation of the bobbin concentrate on the lower surface of the bobbin, thus making structures of the bobbin and the base complicated.
Further, the conventional voice coil motor is problematic in that the structures of the bobbin and the base are complicated, so that it is difficult to create a configuration or a shape for inhibiting foreign substances from flowing through the base into the image sensor module.